1. Field of the Invention
The subject invention relates to paint shields, paint shielding methods, and handles and holders for paint shields
2. Disclosure Statement
The following disclosure statement is made pursuant to the duty of disclosure imposed by law and formulated in 37 CFR 1.56(a). No representation is hereby made that information thus disclosed in fact constitutes prior art, inasmuch as 37 CFR 1.56(a) relies on a materiality concept which depends on uncertain and inevitably subjective elements of substantial likelihood and reasonableness and inasmuch as a growing attitude appears to require citation of material which might lead to a discovery of pertinent material though not necessarily being of itself pertinent. Also, the following comments contain conclusions and observations which have only been drawn or become apparent after conception of the subject invention or which contrast the subject invention or its merits against the background of developments which may be subsequent in time or priority.
The current proliferation of high-pressure spray guns among unskilled people, such as through purchase or rental from wholesale paint stores, is giving rise to various problems including serious hand injuries which are difficult to treat as, for instance, reported in an article by Cameron A. Gillespie, M.D., et al, entitled "Airless Paint Gun Injuries: Definition and Management," which appeared in THE AMERICAN JOURNAL OF SURGERY, Vol 128, Sept. 1974, pp. 383-391. Reference should also be had to an article by Herbert H. Stark, M.D on "Paint-Gun Injuries of the Hand," which appeared in THE JOURNAL OF BONE AND JOINT SURGERY, Vol. 49-A, No. 4, pp. 637-647, June 1967. As apparent from that article, high-pressure airless spray guns bring about serious and tragic injuries not readily preventable by existing safetey devices. Also, as apparent from CONSUMER REPORTS, June 1978, p. 333, the Consumer Product Safety Commission found many existing guards ineffective to provide the requisite protection. Moreover, general practitioners do not necessarily know how a spray gun injury should be treated, thereby increasing their danger, as apparent from ABSTRACTS, Vol. 62, No. 3, summarizing an article by Dr. C. M. Booth, entitled "High Pressure Paint Gun Injuries," from the British Medical Journal, 1333, 1977. Furthermore, spray gun injuries frequently are difficult to detect on admission of the patient, as noted in an article by Erkki O. Karaharju and Par Slatis, entitled "Angiography after Paint-Gun Injury of the Hand: a Case Report," which appeared in INJURY, Vol. 9, pp. 66-67, and in an article by John J. Silsby, M.D. entitled "Pressure Gun Injection Injuries of the Hand," and having appeared in THE WESTERN JOURNAL OF MEDICINE, 125: 271-276, Oct. 1976.
Traditional shields which require or by their form encourage the presence of the painter's hand at the shield, when the same is used on vertical walls or ceilings, obviously do nothing to alleviate the above mentioned problems This, for instance, applies to the wall protecting device disclosed in U.S. Pat. No. 695,965, by F. L. Taylor et al, issued Mar. 25, 1902, the paint shielding device shown in U.S. Pat. No. 3,330,253, by H. W. Rowe, Jr., issued July 11, 1967, the corner painting shield disclosed in U.S. Pat. No. 4,235,192, by T. G. Brubaker, issued Nov. 25, 1980, and the interior decorators' aid disclosed in British patent specification No. 1,400,406, published July 16, 1975.
Other paint shields have handles that are close to the work as to be incapable of effectively alleviating the above mentioned problems. This, for instance, applies to the wall protector of U.S. Pat. No. 456,775, by M. T. Prescott, issued July 28, 1891, the wall shield of U.S. Pat. No. 624,796, by R. L. Hardin, issued May 9, 1899, the paint guard disclosed in U.S. Pat. No. 1,386,706, by L. W. Hall, issued Aug. 9, 1921, the wall protector of U.S. Pat. No. 1,434,903, by C. V. Manning, issued Nov. 7, 1922, the painting tool disclosed in U.S. Pat. No. 1,851,497, by J. Darling, issued Mar. 29, 1932, the painting and cleaning guard of U.S. Pat. No. 2,517,220, by J. S. Lister, issued Aug. 1, 1950, the L-shaped wall protector of U.S. Pat. No. 2,538,743, by W. L. Alston, issued Jan. 23, 1951, the painting guide ruler of U.S. Pat. No. 3,536,041, by J. A. Hill, issued Oct. 27, 1970, the paint shield disclosed in U.S. Pat. No. 3,693,589, by J. W. Knox, issued Sept. 26, 1972, the paint and stain shield of U.S. Pat. No. 4,051,808, by W. Trupp, issued Oct. 4, 1977, the paint guide disclosed in U.S. Pat. No. 4,241,693, by A. M. Shotwell, issued Dec. 30, 1980, and the painting guard disclosed in British patent specification No. 581,704, by J. G., Talbot, dated Apr. 14, 1944.
Several shielding devices have been proposed in the past for use on windows, as may, for instance, be seen from U.S. Pat. No. 2,290,472, by J. V. Hendrick, issued July 21, 1942, U.S. Pat. No. 2,672,122, by E. J. Kupec et al, issued Mar. 16, 1954, and U.S. Pat. No. 3,863,601, by E. A. Eckart, Jr., issued Feb. 4, 1975. Through the use of adhesive devices or suction cups, these masking shields are self-supporting and do thus not require the presence of the painter's hand at the painting location. However, adhesives and suction cups generally are only usable on glass panes and in other limited circumstances, so that these prior shields at best have only a restricted utility.
The same applies in effect to devices that have been tailored to a particular purpose, such as the mop board protector of U.S. Pat. No. 1,563,889, by F. W. Zastrow, issued Dec. 1, 1925, the shield for wall moldings of U.S. Pat. No. 2,332,579, by C. F. Kirby, issued Oct. 26, 1943, the painter's door shield of U.S. Pat. No. 3,029,782, by B. S. Eure, issued Apr. 17, 1962, and to a large extent also to the work attached paint shield disclosed in U.S. Pat. No. 3,380,435, by E. J. Wagner, issued Apr. 30, 1968.
An interesting situation is apparent from juxtaposition of U.S. Pat. No. 2,545,638, by S. Wheatley, issued Mar. 20, 1951, for a portable paint mask, and U.S. Pat. No. 3,942,472, by E. O. McAlister, issued Mar. 9, 1976. In particular, while the Wheatley renewable paper shield was designed for engagement of a close handle portion by the painter's hand, McAlister provides a similar apparatus with an elongate handle tiltable into various angular positions. Unfortunately, both of these devices are of such complexitiy in design and operation as to be of unlikely widespread use.
A supposedly more practical use is apparent from U.S. Pat. No. 2,289,136, by A. J. Matter, issued July 7, 1942, and showing a painter's masking device with a short handle. Again, that device appears to have been tailored to use at windows and window frames and in other special circumstances.
The paint shield of U.S. Pat. No. 3,528,388, by B. P. McLain, issued Sep. 15, 1970, has a handle spaced from the shield, but is restricted in design to use at roof surfaces. The splash guard of U.S. Pat. No. 3,538,532, by J. P. Shortino et al, issued Nov. 10, 1970, is limited by design to use on paint rollers. The paint guard device of U.S. Pat. No. 4,217,854, by C. E. Brown, issued Aug. 19, 1980, has a convenient way of attaching a handle by means of an internal thread in an edge of the paint shield, receiving a threaded end portion of an elongate handle. In practice, that paint shield would, however, appear to be expensive to manufacture and not suitable for general use, in that it requires the inclusion of crossed sets of multitudes of flexible reforcing elements.
A paint shield particularly made for spray guns is apparent from U.S. Pat. No. 2,842,093, by K. V. O'Neill, issued July 8, 1958. In practice, that paint shield weighs heavily on the paint gun and would be impractical in many situations. By way of general observation, professional painters are wont to remove or to neglect using safety devices that are complex or tend to interfere with their modus operandi.
Another common observation with painters is their aversion to handling small mechanical devices. Reference may in this respect be had to U.S. Pat. No. 2,484,607, by G. A. Cherem, issued Oct. 11, 1949, and showing a paint guard having an elongate handle attachable thereto at an angle by a nut and bolt combination. In practice, painters usually do not carry a wrench and screwdriver set for satisfactorily servicing such a combination. Also, experience shows that such mechanical devices are easily contaminated by paint or rendered ineffective thereby. The painting shield disclosed in U.S. Pat. No. 4,085,703, by F. J. Glowacki, issued Apr. 25, 1978, somewhat alleviates the latter problem by proposing the use of a wing nut for fastening a tiltable elongate handle. However, a wing nut that projects from the paint shield or shield support may in practice somewhat interfere with the work or at least become stuck when dripping paint is accumulating on the thread of the associated projecting bolt. The paint shield support by Glowacki also employs a pair of clips of the type used in paper clipboards for about a century, as may, for instance, be seen from U.S. Pat. No. 314,769, by H. C. Yeiser, issued Mar. 31, 1985, U.S. Pat. No. 757,937, by W. Lukes, issued Apr. 16, 1904, and U.S. Pat. No. 799,873, by L. Senge, issued Sep. 19, 1905.
Although the structure of the mentioned Glowacki paint shield holder does enable more rapid changing of shield members than typical prior devices, it relies for its gripping action upon a spring-type clip which is essentially mechanical and thereby exposed to contamination by paint, and which engages a retained paint shield along linear edges corresponding in size only to the cross-section of each spring clip body. In consequence, the paint shield comes loose or undesirably changes its position in the holder when the same is bumped, jarred or otherwise rapidly changed in position preparatory to or during painting operations. In practice, the spring tension which can be provided for forcing each spring clip into engagement with a paint shield is limited by the potential danger of accidentally pinching the user's fingers when the paint shield is installed into or removed from the prior holder, necessitating a depression or hand manipulation of the spaced spring clips on the holder. Also in practice, the said limited spring tension of said linear clip practically requires the use of disposable cardboard shield inserts, since heavier or more slippery materials used as shield members in said patented device are held too loosely to fuction either safely or efficiently. As a matter of recent observation, paint shield holders sold under the mentioned Glowacki patent do no longer in structure correspond to the claims thereof. The trend appears to be toward simpler and more straightforward structures as may, for instance, be seen from U.S. Pat. No. Des. 248,725 and U.S. Pat. No. 4,248,914, both by R. A. McClane, issued Aug. 1, 1978 and Feb. 3, 1981, respectively. Unfortunately for the practical painter, however, that design also relies on mechanical nut-and-bolt arrangements for attaching a reinforced paint shield edge to a narrow handle connector.
A currently marketed paint shield for homeowner use combines a rigid blade with a lightweight plastic paint guard and plastic foam handle in an effort to reduce painter fatigue. However, heavier solid straight and angled aluminum shields as well as solid plastic counterparts thereof are currently of most widespread use among professional spray painters. The designs of all of these are such as to practically require the handle to remain permanently attached to the solid shield or shield holder. In practice, however, the presence of a handle at a paint shield or paint shield holder is not always necessary or desirable. Rather, the absence of the handle is often preferable or necessary, while other situations require the availability of selectively attachable and detachable handles of different lengths.
The corner shields and paint spraying methods disclosed in my U.S. Pat. No. 4,331,716, issued May 25, 1982, successfully deal with these problems in many situations, particularly at door frames and similar projecting corners where my paint shields can be suspended, thereby keeping the painter's hand away from the work area, or at corner regions where the painter can hold the shield at a leg thereof remotely from the area of the angled shield where painting is taking place at the moment. While my patented corner shields thus avoid the above mentioned dangers and satisfy the indicated need in many situations, there also exists a need for a paint shield holder which permits a use of paint shields of various dimensions flexibly with or without handles and preferably two or more handles of different lengths, readily exchangeable without a need of nuts, bolts, spring clips or other mechanical contrivances.
Another need which persists is for a paint shield in which migration of paint over an edge portion of the shield from one major surface to the opposite major surface thereof is avoided. Even in spray painting, paint accumulates at an edge portion thereof facing the spray paint gun, as the shield is being used to shield areas adjacent surfaces being painted against the spray paint. In practice, such accumulated paint migrates by gravity capillary action, or otherwise over the solid free edge portion of the paint shield and eventually contaminates the areas which are supposed to be shielded.
A further need exists for a reusable solvent-proof paint shield which is lightweight in comparison with reusable shield members currently available. The combined weight of a solid shield member, holder, handle, and wet paint can be cumbersome and even dangerous, especially during overhead ladder work when the painter may be tired and more prone to becoming unbalanced by hand-maneuvering these contrivances in combination with spray guns, hoses, brushes, or other spray painting equipment.